There will not be too many afternoons at Celtic Park that fall flat.

Saturday’s encounter against St Johnstone seemed like a hangover from the party of Champions League qualification, but it is a performance that is unlikely to be glimpsed too often this season.

Scott Sinclair, Celtic’s best player at the weekend, was the only one who really showed the kind of zip and energy that is associated with the Parkhead side under Brendan Rodgers and, yet, they could still have pipped Saints to all three points here.

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Sinclair hit the bat late on, Mikael Lustig was denied by the woodwork but ultimately it was a performance that was rescued by a late goal from substitute Callum McGregor.

The midfielder has been overlooked by Gordon Strachan for the national team but if McGregor continues to prove his worth to Celtic by virtue of his performances, it won’t be too long before he is sighted in the colours of his country.

Rodgers was irked by the player’s exclusion from the international fray and there was a hint of annoyance too with the impatience of a support who feared that Saturday might have been the day that the invincible tag was lost.

As it was, McGregor’s goal maintained that run at 53 and counting – 52 of which have come under Rodgers – ensuring that Celtic head into the break for international football in pretty fine fettle.

The main ambition this summer was for the barrier to the Champions League to be negotiated in the six qualifying games. That Celtic have achieved what is their prime objective every season is cause for the club now to kick back and take a breather before the fraught nature of the next few months.

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Between now and Christmas Celtic will be involved in midweek games and travel and the expectancy is that this will lead to further exposure of some of the young players who have come to the fore over the last few months.

Anthony Ralston was back in place for the weekend visit of St Johnstone and while he may have felt a sense of disquiet at the manner of the goal conceded to Steven MacLean, it was Craig Gordon who would have lost some sleep over it.

The Celtic goalkeeper had kicked the ball to right-back Ralston after the youngster had initially sent a passback to him from near the corner flag. Under pressure from MacLean, the keeper returned the pass to Ralston and the teenager, instead of kicking the ball up field, passed back once more Gordon.

As the ground lulled and play stopped, all appearing to suspect that MacLean was offside – he wasn’t – there was a sense of slow motion as MacLean netted and then turned to check that there was no flag before racing off to celebrate.

MacLean could count himself lucky on two fronts as the game progressed; one that he was not red-carded for an incident with Tierney when he appeared to use his forearm after tussling with left-back and, two, that referee Willie Collum booked him for the infringement.

The decision to penalise with a yellow card means that even if a repeat viewing would suggest the incident merited a more serious penalty, the fact that the referee took action at the time will mean that the compliance officer cannot revisit it.

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For Rodgers, now, the game brings down the curtain on the opening chapter of a season that he expects to be as fruitful as last. There was an inevitable leggishness about Celtic after the lengthy flight and gruelling nature of the game against Astana but so far as things go, it is difficult to see the first few weeks of the season as being anything other than what Celtic would have wated.

"We have three wins and a draw in the league, we're in the quarter-final of the League Cup and also qualified for the Champions League, so it’s been a great start to the season for us,” said Rodgers afterwards.

“The players, in the second-half, showed their heart, spirt and desire to not the lose the game. That’s something we’ve created here within the squad. Tommy [Wright] and his team defended well but my players were absolutely brilliant. We did everything we could to get the win but we couldn’t so we’ll take the point.

“For the last 30 minutes, I thought the players were exceptional in the energy they showed and the quality. We could have scored one or two more. It was a mixture of some great defending by St Johnstone and their goalkeeper making some amazing saves."

Celtic will give those not involved in international football a break towards the end of this week as they gear up for another stint at the Champions League.

The next couple of months promises much in the way of excitement and intrigue.